I have a much MUCH warmer, wetter climate. My impression from other posters, closer to you, is "yes" - but I'll defer to their experience on that question.
Well yes. Depending on the depth of the bird's mouths. Those are rather shallow. If they are 3/4", then your 3" x 14.5" approximation above is almost exactly right. I really should have put my glasses on and looked at the photo more closely. On a roof this shallow, I don't usually even...
"Yes"
A predator protected, free opening with some shelter from wind blown rain is exactly what you want and need. My inclination would be to put the human door on the gable end facing away from your fence, extend the roof line 3' or so in that direction (now giving you a weather sheltered...
At 3.5 x 14.5, each opening between your 2x4 rafters represents 50.75 sq inches, which you should approximate as 1/3 sq ft. As there are 6 such openings on each side, that's 4 sq ft free ventilation, 24/7/365.
Most manufacturers, either on the packaging, or their website, will publish the free...
I understand. I expected you would have a $14 "wavy" option at 8', and a $16 (or perhaps $17) 5v pattern available to you - that's the case for me. Surprised by your store's stocking options.
and yes, at basically double the price, its not worth it. Not even close. But I would recommend...
Yes. BUT.
Yes. You can use them.
I prefer the "5V" pattern. It has big flat "landing zones", very easy to ensure the screw goes straight thru, straight into the purlin, no gap. The continuous undulations of the "wavy" panels make that a little harder. I also find them easier to walk on...
Rafter as usual, whatever spacing you feel appropriate. Install purlins (1x4s or 1x6s or 5/4x6 deck boards). Two screws, every place a purlin crosses the rafter, screw length of "purlin + 1/3 to 1/2 rafter thickness" - so if I framed with 2x4 rafters and used a 1x4 purlin, I'd look for screws...
I've seen people mix the Suntuff panels with steel panel roofing having the same profile, to allow some passive solar lighting under an otherwise steel roof, since the framing below is identical, its easy to assemble the pieces with very limited concerns re: water leak/penetration. Sadly...
Most creatures want to dig as little as possible. Its why a dog will dig right next to the fence, instead of several feet away, and why they dig the bare minimum to slip undrr a fence,rather than deep down and tunneling.
That's why you typically only have to go down 1 ft or so into the soil...
Apologies @junior67 , did not mean to hijack your thread in response to the other poster. Hopes you have a rewarding and successful chicken experience, you seem to be off to a great start, and you are clearly a conscientious owner. All kept animals should be so lucky.
Speaking only for myself, as a frequent poster offering the offending "4 sq ft/" comment, I do emphasize that the "rule of thumb" or general recommendation is 4/10/1 - 4 sq ft house, 10 sq ft run, 1 sq ft free ventilation - and then I go on to talk about the importance of thinking of the whole...
...and on the subject of arbitrary rules, 2x6s 16"oc is one of those. Whether to use a 2x6 or a 2x4 or a 2x8 or more, 12"oc, 16"oc, 24"oc, etc is a factor of span and load. Larger boards (or doubled timbers) allow greater spans, as does the use of LVL as opposed to southern yellow pine...
Better that a recommendation be given for "too much" (truly, "excess" or "above minimum") space which is suitable for most than to suggest the bare minimum adequate to intensive farming practice. Your own example, "The winter run area on the other hand is darn close to 5 sqft per bird" is...
I have a raised coop that's 8x12, supported 3' off the ground on some 4x4s. I have ducks, they nest on the ground, so the "under" is their spot. Its a 4x8 sheet a 4x4 sheet and a 4x8 sheet for the floor, in the shape of a "U" so I can walk in, and nothing is more than 4' away (ok, corners are...
Brahmas are big birds (eventually). Cochin aren't small, either. Before you go too much further, I suggest you give some thought (space permitting) to increasing the coop size to 8x8 - fewer cuts, not much more lumber - and pushing the run out to 8x12.
Much easier to do now than to redo later...